Best multi-agent frameworks for Java and the JVM
Few multi-agent frameworks have a first-party Java SDK. This page lists the ones in this directory that do, with what each record says about feature gaps compared with the same vendor's other SDKs. Data as of 2026-09-30.
Selection criteria
- Has a first-party Java SDK or implementation.
- Documents a multi-agent model available in Java, not only in other languages.
- Documents human approval in Java.
- Protocol coverage with evidence.
- Vendor's stated direction for the Java line.
Shortlist
- Spring AI Alibaba: Apache-2.0 framework on Spring AI (JDK 17+) with sequential, parallel, routing and loop multi-agent flows, a graph runtime with checkpoints,
HumanInTheLoopHookapprovals, MCP and A2A over Nacos. Its overview says ReactAgent now mainly gets fixes and points to AgentScope. - Agent Development Kit (ADK) for Java: Google's Apache-2.0 ADK for Java:
LlmAgentwith sub-agent transfer, sequential, parallel and loop workflow agents and MCP toolsets. A2A and tool confirmation are marked experimental, and graph workflows are documented for other languages only. - AgentScope: Apache-2.0 framework whose FAQ lists a separate Java implementation next to Python and TypeScript; the record's permission system, pipelines and protocol evidence describe the Python SDK, so check the Java repository for parity.
- Semantic Kernel: MIT SDK with a Java edition, but the record notes that agent orchestration is not yet available in Java and that Microsoft names Agent Framework (Python and .NET) as its successor.
Shortlist facts
| Tool | Type | Languages | License | Pricing | Pattern | MCP | A2A | AG-UI | Stars |
|---|---|---|---|---|---|---|---|---|---|
| Spring AI Alibaba | Framework | Java | Apache-2.0 | Open source, free | Graph | Yes evidence | Yes evidence | Unknown | 10,948 |
| Agent Development Kit (ADK) for Java | Framework | Java | Apache-2.0 | Open core | Handoff | Yes evidence | Partial evidence | Unknown | 1,741 |
| AgentScope | Framework | Python, TypeScript, Java | Apache-2.0 | Open source, free | Supervisor | Yes evidence | Yes evidence | Yes evidence | 32,617 |
| Semantic Kernel | Framework | C#, Python, Java | MIT | Open source, free | Other | Yes evidence | Partial evidence | Unknown | 28,613 |
FAQ
Does Microsoft Agent Framework support Java?
No Java SDK is documented. It covers Python and .NET, with Go in public preview.
Is LangChain4j listed?
Not in this edition of the directory. Only tools with a reviewed record are ranked.
Which Java option supports A2A?
Spring AI Alibaba documents A2A (through Nacos registration). Google ADK for Java has an experimental A2A module, recorded as partial.